Public Database could not mounted,

Hello, I have the problem that the public folder database could not be mounted. Error: Public Folder Database An Active Manager operation failed. Message: ... MapiExceptionJetErrorTableDuplicate: Unable to mount database. (hr=0x80004005, ec=-1303) .. [Database: Public Folder Database, Server: SBS2008.ai-dom.local]. I did: eseutil /P eseutil /d eseutil /g eseutil /mh (clean shutdown displayed) But no success. Could anybody help or has anybody a hint? Thanks Kai from germany